Expandable suture anchor

ABSTRACT

An expandable suture anchor is provided for use with an applicator. The suture anchor has a body formed from a biocompatible spring material such that the suture anchor has a first configuration when positioned within the applicator and a second configuration after deployment from the applicator, wherein the second configuration has a geometric shape that is broader in at least one plane than the first configuration.

BACKGROUND

The present application relates to surgical fasteners and instrumentsfor approximating and fastening tissue and, more particularly, to sutureanchors and associated instruments for endoscopically attaching suturesto tissue.

The working channel of a flexible endoscope typically has a diameter inthe range of about 2.5 to about 4 millimeters. Current staplers andsuturing devices cannot be easily redesigned to work through such smallopenings. In addition, performing procedures by way of the workingchannel does not easily permit using two instruments positioned atdifferent angles with respect to the wound site in order to “pass andcatch” a needle and apply sutures.

Various clips, suture fasteners and anchors have been developed suchthat physicians (e.g., gastroenterologists) may endoscopically closeperforations in the gastrointestinal tract resulting from, for example,ulcers or polypectomy. One type of suture anchor is known as a “T-tag”fastener. The T-tag is a small metallic pin with a suture attached atthe middle. The physician may load the T-tag into the end of acannulated needle of an applicator that may be inserted through theworking channel of a flexible endoscope. The physician may push theneedle into the tissue near the perforation and implant the T-tag intothe tissue with the attached suture trailing through the working channeland out the proximal end of the endoscope. After two or more T-tags areattached to the tissue near the wound in this manner, the physician maypull the sutures to appose the tissue around the wound. The physicianmay then fasten the sutures together by applying a plurality ofalternating, right and left overhand knots using a knot pushing deviceor by applying a knotting element or other type of fastener through theworking channel of the endoscope.

In order for T-tags to resist pull-out from the tissue when the attachedsuture is tensioned, the T-tag should rotate after ejection from thecannulated needle to be approximately perpendicular to the attachedsuture. An issue typically associated with anchors such as the T-tag isthat if the anchor is implanted within tissue layers, rather thanthrough tissue layers such that the anchor cannot reorient as described,it is possible for the T-tag to be easily pulled from the hole createdby the penetrating needle.

Another issue typically associated with current suture anchors such asthe T-tag is the occasional situation in which the anchor comes out ofthe distal end of the cannulated needle while the applicator ismanipulated into the endoscope and towards the wound site.

An issue typically associated with current suture anchor applicators isthe risk that nearby organs may be accidentally injured by the needle ofthe applicator. The physician normally cannot see anatomical structureson the distal side of the tissue layers when the needle is being pushedthrough the tissue layers. Therefore, there is a risk that adjacentorgans may be accidentally injured by the penetrating needle.

In addition to addressing the above issues, it may be desirable toprovide an improved suture anchor that is magnetic resonance imaging(MRI) compatible. For example, the anchor may be formed from anon-ferrous material.

Accordingly, there is a need for an improved suture anchor that may besecurely retained in a suture anchor applicator until deployment intothe tissue near a wound. In addition, there is a need for a sutureanchor with improved resistance to pull-out from tissue, whetherimplanted within tissue layers or through tissue layers. Furthermore,there is a need for an improved suture anchor and suture anchorapplicator that helps to prevent accidental injury to nearby anatomicalstructures during deployment of the anchor into tissue near a woundsite. Finally, there is a need for an improved suture anchor that may beformed from a non-ferrous material in order to be MRI compatible.

SUMMARY

In one embodiment, an expandable suture anchor is provided for use withan applicator. The suture anchor includes a body formed from abiocompatible spring material such that the suture anchor has a firstconfiguration when positioned within the applicator and a secondconfiguration when deployed from the applicator, wherein the secondconfiguration has a geometric shape that is broader in at least oneplane than the first configuration.

In another embodiment, an expandable suture anchor for use with anapplicator includes a body formed from a nickel-titanium memory materialsuch that the suture anchor has a first configuration when positionedwithin the applicator and a second configuration after deployment fromthe applicator. The second configuration has a geometric shape that isbroader in at least one plane than the first configuration. The body hasan approximately cylindrical shape defining a longitudinal axis when inthe first configuration and includes at least one leg that is springablydeformable such that a portion of the leg extends further in anoutwardly direction from the axis in the second configuration than inthe first configuration. The suture anchor also includes a surgicalsuture threaded through an aperture of the body and retainably attachedto the body by a knot in the suture or a ferrule crimped onto the sutureto the body, wherein the suture extends from approximately the middle ofthe body when in the second configuration.

In another embodiment, an expandable suture anchor for use with anapplicator includes a body formed from a planar sheet of anickel-titanium memory material that is configurable into a roll suchthat the suture anchor has a first configuration when positioned withinthe applicator and a second configuration after deployment from theapplicator, wherein the second configuration has a geometric shape thatis broader in at least one plane than the first configuration. Thesuture anchor also has a surgical suture threaded through an aperture ofthe body and retainably connected to the body by a knot in the suture ora ferrule crimped onto the suture, wherein the suture extends fromapproximately the middle of the body when in the second configuration.

Other aspects and embodiments of the expandable suture anchor willbecome apparent from the following description, the accompanyingdrawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing of a flexible, endoscopic portion of a gastroscopeinserted into the upper gastrointestinal tract of a patient;

FIG. 2 is a drawing of the distal portion of a suture anchor applicatorextending from the distal end of the gastroscope while a first sutureanchor is deployed into the stomach wall near a wound;

FIG. 3 is a drawing of the applicator of FIG. 2 while a second sutureanchor is deployed into the stomach wall on the opposing side of thewound;

FIG. 4 is a drawing of the applicator of FIG. 2 while a pair of suturesof the first and second suture anchors are drawn together to appose thetissue on each side of the wound;

FIG. 5 is a drawing of the pair of sutures of FIG. 4 fastened togetherwith a knotting element, thereby holding the tissue in apposition;

FIG. 6 is a longitudinal sectional view of the distal portion of a firstembodiment of a suture anchor applicator, shown while a suture anchor isin a loaded position;

FIG. 7 is a longitudinal sectional view of the applicator shown in FIG.6, shown after the suture anchor has been deployed;

FIG. 8 is a perspective view of a first aspect of a suture anchor whilein an unconstrained configuration;

FIG. 9 is a drawing of the suture anchor of FIG. 8 after placementthrough the tissue layers;

FIG. 10 is a perspective view of a second aspect of a suture anchorwhile in an unconstrained configuration;

FIG. 11 is a drawing of the suture anchor of FIG. 10 after placementwithin the tissue layers;

FIG. 12 is a perspective view of a third aspect of a suture anchor whilein an unconstrained configuration;

FIG. 13 is a drawing of the suture anchor of FIG. 12 after placementwithin the tissue layers;

FIG. 14 is a perspective view of a fourth aspect of a suture anchorwhile in a constrained configuration;

FIG. 15 is a drawing of the suture anchor of FIG. 14 after placementthrough the tissue layers;

FIG. 16 is an perspective view of a fifth aspect of a suture anchorwhile in an unconstrained configuration;

FIG. 17 is a longitudinal sectional view of the suture anchor of FIG.16;

FIG. 18A is a perspective view of a second embodiment of a suture anchorapplicator, including a sectional view of a handle;

FIG. 18B is a perspective view of the distal portion of the applicatorshown in FIG. 18A, including a tissue stop shown in an expandedconfiguration;

FIG. 19 is a longitudinal sectional view of the distal end of theapplicator shown in FIG. 18, showing the suture anchor of FIG. 16 in aloaded position and the tissue stop in a collapsed configuration;

FIG. 20 is a longitudinal sectional view of the distal end of theapplicator shown in FIG. 18, showing the suture anchor of FIG. 16 in aloaded position and the tissue stop in an expanded configuration;

FIG. 21 is a perspective view of the distal portion of a thirdembodiment of a suture anchor applicator, including a second aspect of atissue stop shown in a collapsed configuration;

FIG. 22 is a perspective view of the distal portion of the applicatorshown in FIG. 21, showing the tissue stop in an expanded configuration;

FIGS. 23, 24, 25, 26, 27 and 28 illustrate a method of attaching asuture anchor to the tissue of a patient, showing the distal portion ofthe applicator and the suture anchor of FIG. 21, wherein FIG. 23 showspositioning the distal end of the applicator containing the sutureanchor near the tissue, FIG. 24 shows pushing the suture anchor againstthe tissue, FIG. 25 shows piercing the needle tip of the suture anchorinto the tissue, FIG. 26 shows penetrating the suture anchor and thedistal end of the applicator through the tissue to a predeterminedmaximal penetration depth, FIG. 27 shows deploying the suture anchor,and FIG. 28 shows withdrawing the applicator from the tissue such thatthe suture anchor is attached to the tissue; and

FIG. 29 is a perspective view of the distal portion of a fourthembodiment of a suture anchor applicator.

DETAILED DESCRIPTION

FIG. 1 illustrates a flexible endoscopic portion 16 of a gastroscope 14inserted into the upper gastrointestinal tract of a patient. FIGS. 2, 3,4 and 5 illustrate a procedure for repairing a wound such as a gastricbleeding ulcer in the stomach wall of the patient via the workingchannel of gastroscope 14. As shown in FIG. 2, the physician (e.g.,gastroenterologist) inserts a suture anchor applicator 18 throughgastroscope 14 and penetrates a cannulated needle 19 through the stomachwall near the diseased area or wound. Needle 19 contains at least onesuture anchor such that, as shown in FIG. 3, the physician may deploy afirst suture anchor 20 attached to a first suture 24 to one side of thewound and a second suture anchor 22 attached to a second suture 26 tothe opposite side of the wound. First and second suture anchors 20, 22may be conventional “T-tag” fasteners or any of the suture anchorembodiments described herein or their equivalents. The free ends offirst and second sutures 24, 26 may extend through the proximal end ofgastroscope 14 such that, as shown in FIG. 4, the physician may draw thefirst and second sutures 24, 26 together to appose the tissue around thewound. The physician may then fasten the first and second sutures 24, 26together by, for example, applying a plurality of alternating, right andleft overhand knots using a knot pushing device (not shown) or byapplying a knotting element 28 or other type of fastener, as shown inFIG. 5, by way of the working channel of gastroscope 14. Excess suturemay be trimmed near the knot using an endoscopic cutting instrument.

When using conventional T-tag fasteners with the technique shown inFIGS. 2-5, there are necessary conditions for the T-tag fasteners tobecome securely attached to the tissue. For example, it is importantthat the T-tag fastener reorient with respect to the suture aspreviously described such that the T-tag may not be easily pulledthrough the tissue. If the T-tag is positioned within the tissue ratherthan completely through the tissue into a body cavity, the T-tag stillmust reorient to some degree such that the suture is securely attachedto the tissue.

Although the size of the cannulated needle 19 shown in FIG. 2 may vary,it may have an inner diameter of less than one millimeter. Consequently,suture anchor 22 must be very small to be loaded inside of needle 19,yet once deployed into tissue, must be sufficiently broad to resistpull-out from tissue such that considerable tension may be applied tothe sutures to draw together the tissue. Therefore, it would bedesirable for suture anchor 22 to expand once deployed from theapplicator and/or to include features to help secure anchor 22 to thetissue. In addition, it would be desirable for suture anchor 22 toremain securely in the loaded position within applicator 18 prior todeployment into tissue to avoid the time-consuming steps of withdrawing,reloading and reinserting the applicator.

Recently, a number of medical devices have been developed that providean auxiliary passageway along the outside of the endoscope. One exampleof a medical apparatus that provides an auxiliary endoscopic passagewaymay be found in U.S. patent application Ser. No. 10/440,957 (publishedas U.S. Pat. Pub. No. 2004/0230095), filed May 12, 2003, and assigned toEthicon Endo-Surgery, Inc. The auxiliary passageway may be used, perhapsin combination with the working channel of the endoscope, for severalpurposes, such as to insert a suture anchor applicator for access to aninternal wound site. It should be understood, therefore, thatdescriptions herein referring to the working channel of the endoscopealso include using such an auxiliary passageway.

FIGS. 6 and 7 are longitudinal sectional views of the distal portion ofa first embodiment of a suture anchor applicator 30, which may be usedin the same manner as described for applicator 18 of FIGS. 2 and 3. InFIG. 6, a first aspect of a suture anchor 52 is shown in a loadedposition in applicator 30. In FIG. 7, suture anchor 52 is shown deployedfrom applicator 30. Applicator 30 may have a shaft .31 that includes aninner tube 40 and an outer tube 42. In a first aspect of applicator 30,shaft 31 may be adapted for insertion into the working channel of aflexible endoscope, including a gastroscope and a colonoscope, by beingflexible and having an outer diameter approximately in the range of 2 to3.8 millimeters and a length of approximately one and a half meters. Ina second aspect of applicator 30, shaft 31 may be adapted forpercutaneous or laparoscopic applications and be relatively rigid andstraight, and may have a length approximately in the range of 20-30centimeters.

Outer tube 42 may be formed from an extruded polymer, a helically woundmetallic wire or from other materials well-known in the art. Inner tube40 may be formed from 19 gage stainless steel hypodermic tubing, forexample, having an outer diameter of approximately 0.043 inches (1.09millimeters) and a wall thickness of approximately 0.003 inches (0.076millimeters). The distal end of inner tube 40 may be ground to form acannulated needle 32 having a distal, penetrating tip 34. Alternatively,inner tube 40 may be formed from an alternate type of metallic orpolymeric tube and attached to cannulated needle 32, such as by welding,crimping, gluing or other conventional method.

Penetrating tip 34 may be ground to have a “bi-angular” configuration asshown in FIG. 6. To facilitate placement of the suture anchor into thebody, the outer surface of needle 32 may be textured, coated orotherwise processed to enhance the ultrasonic reflectivity of needle 32such that the physician may view needle 32 from outside of the patient'sbody using, for example, a handheld ultrasonic imaging device.

Inner tube 40 and needle 32 may include a channel 36 extending along alongitudinal axis 50 between the proximal and distal ends of applicator30. At least one suture anchor 46 having a suture 48 attached theretomay be loaded in channel 36. An actuating element 38 may extend throughchannel 36 of applicator 30 for ejecting suture anchor 52 out of needle32, as shown in FIG. 7.

Outer tube 31 may be moved between an extended position for shieldingtip 34 of needle 32 (FIG. 6) and a retracted position for exposing tip34 of needle 32 (FIG. 7). Shaft 31 may be inserted into the workingchannel or auxiliary passageway of the endoscope with suture 48 trailingin the diametral clearance between shaft 31 and the inside of theworking channel or passageway, such that the free end of suture 48 mayextend out of the proximal end of the channel or passageway.

Expandable Suture Anchor

Numerous aspects of an expandable suture anchor are described herein. Ingeneral, the expandable suture anchor may be used for attaching a sutureto any one of numerous soft tissues, including the wall of thegastrointestinal tract. The anchor may include a suture attached theretoand a body that is constrainable to a first configuration for deploymentinto the tissue and that is expandable when unconstrained to a secondconfiguration for resisting pull-out from the tissue.

FIG. 8 is a perspective view of the first aspect of the suture anchor 52shown with applicator 30 in FIG. 6. FIG. 9 shows anchor 52 afterplacement through tissue layers such as the stomach wall. Anchor 52 mayinclude a body 56 having a bifurcated portion 58 along an anchor axis 64and forming a pair of legs 60. Bifurcated portion 58 may include anangled portion 59 that splays away from axis 64. Angled portion 59 has alength indicated by “L1” that may vary, for example, betweenapproximately one eighth and one quarter of the overall length of anchor52. Anchor 52 may have a first configuration when constrained in theloaded position in needle 32 (see FIG. 6) and a second configurationwhen unconstrained as shown in FIG. 8. Anchor 52 may have a relativelyshort, angled portion 59 as depicted in FIG. 8 to help retain anchor 52securely inside of needle 32 until deployment of anchor 52 into tissue.Anchor 52 may be positioned inside of channel 36 of needle 32 such thatlegs 60 bear against the inside of channel 36, causing body 56 to bow asshown in FIG. 6.

Anchor 52 may be formed from a biocompatible, spring material such as astainless steel, a titanium alloy, a nickel-titanium memory metal(Nitinol), a polymer, or an absorbable polymer. Spring material shall bereferred to herein as a material such that, a suture anchor formed fromthe spring material is biased to springably change from the first to thesecond configuration when not constrained.

Suture 54 and all the sutures described herein may be a surgical sutureformed from convention surgical suture materials including, for example,cat gut, polypropylene, polyester and stainless steel. The suture sizemay be any one of the commonly used sizes for surgical procedures,including 2/0, 3/0 and 4/0 sutures.

As shown in FIG. 8, anchor 52 may include a bore 66. A suture 54 may beattached to anchor 52 by passing suture 54 through bore 66 and tying aknot 62 that is larger than bore 66. Alternately, a ferrule 47 (see FIG.7) may be crimped onto suture 54. It is also possible to crimp or stakebody 56 onto suture 54 at the end opposite of legs 60. Suture 54 mayalso be glued or mechanically attached to anchor 52, or by any one ofnumerous other conventional methods.

Suture 54 may extend from the middle portion of anchor 52 such that whensuture 54 is drawn tightly after placement of anchor 52 through layersof tissue, anchor 52 reorients such that axis 64 is approximatelyperpendicular to suture 54 extending from the wound site, therebyproviding a high resistance to pull-out from the tissue. If anchor 52 ispositioned within tissue rather than in a body cavity, legs 60 alsofunction to dig into the tissue when a tensile force is applied tosuture 54, thereby helping anchor 52 reorient within the tissue suchthat suture 54 is securely attached to the tissue. The lengths L1 oflegs 60 and the angles formed by legs 60 relative to axis 64 may beselected such that tissue retention forces are asymmetric when a tensileforce is applied to suture 54, thereby helping anchor 52 to reorientwithin the tissue and increase the pull-out resistance.

In one aspect, the diameter of anchor 52 may be approximately 0.50 to0.85 millimeters, or small enough to slide easily, for example, into a19 gage, cannulated needle. The overall length of anchor 52 may be, butis not limited to, approximately five to 10 millimeters.

FIG. 10 is a perspective view of a second aspect of a suture anchor 68.FIG. 11 shows anchor 68 after placement in the tissue layers. Anchor 68has a first configuration when constrained in the loaded position insideof needle 32 of applicator 30 (FIG. 6) and a second configuration whenunconstrained, as shown in FIGS. 10 and 11. The second configuration isbroader in at least one plane than the first configuration. Anchor 68may have at least one leg 80 splayed at an angle or extending outwardlyrelative to a longitudinal axis 84. As shown in FIG. 10, anchor 68 mayinclude a body 74 having a bifurcated portion 76 forming a pair of legs80. Anchor 68 may also have a plurality of legs. For example, anchor 68may have a large plurality of very slender legs formed from stifffilaments and joined together in a “broom-like” fashion. In the lattersituation, the plurality of legs may provide a scaffold for tissueingrowth, which is beneficial for further securing anchor 68 to thetissue.

Anchor 68 is similar to anchor 52 of FIG. 8, except that an angledportion 82 of anchor 68 is longer, as indicated by “L2”, than angledportion 59 of anchor 52. Length L2 may be, for example, approximatelyone quarter to one half of the overall length of anchor 68. Anchor 68may be formed from the same biocompatible, spring materials as describedfor anchor 52. A suture 70 may be attached to anchor 68 by a knot 72, acrimped ferrule, glue or any one of numerous other conventional methods.

Anchor 68 provides a high pull-out resistance from tissue when deployedeither through tissue layers or within tissue layers. In the former,anchor 68 may orient itself to be approximately perpendicular to suture70. In the latter, legs 80 of anchor 68 act like barbs and may dig intosurrounding tissue. In addition, the spring-back of legs 80 helps tohold anchor 68 securely inside of needle 32 of applicator 30 (FIG. 6).

FIG. 12 shows a third aspect of a suture anchor 86 in an unconstrained,second configuration. FIG. 13 shows anchor 86 also in the secondconfiguration, after placement within stomach wall 12. Anchor 86 has aconstrained, first configuration when in the loaded position in needle32 of applicator 30 (FIG. 6). Anchor 86 is a new adaptation of asurgical clip concept disclosed in U.S. Pat. No. 6,447,524, which istitled “Fastener for Hernia Mesh Fixation,” issued to Knodel et al. onSep. 10, 2002 and assigned to Ethicon Endo-Surgery, Inc. Anchor 86 maybe formed from a titanium-nickel memory metal (Nitinol), a stainlesssteel, a titanium alloy, or any one of a number of spring materials.Anchor 86 may include a body 88 having a bifurcation 92 to form a pairof legs 90 that splay or extend outwardly from an anchor axis 100. Asuture 96 may be retained in a hole 94 in body 88 by a knot 98. When inthe loaded position inside of needle 32 of applicator 30 (FIG. 6), legs90 may extend in the distal direction. Like anchor 68 of FIG. 10, anchor86 may provide a high pull-out resistance from tissue when placed boththrough and within tissue layers.

FIG. 14 illustrates a fourth aspect of a suture anchor 102 while in afirst configuration, such as when constrained in a loaded position inneedle 32 of applicator 30 (FIG. 6). FIG. 15 shows anchor 102 placedthrough stomach wall 12, unconstrained and in a second configuration.Anchor 102 has a body 108 that may be formed from a spring material suchas stainless steel, titanium alloy, a polymer or a memory metal(Nitinol) into a thin sheet, flat or plate that may be rolled into theapproximately cylindrical shape of the first configuration. Whenunconstrained in the second configuration, anchor 102 may have arelatively large planar surface area as compared to the projected areaof anchor 102 while in the first configuration, thereby providing a veryhigh pull-out resistance from tissue when placed through tissue layersas shown in FIG. 15. Body 108 may have a rectangular shape with sidedimensions of approximately 5 to 10 millimeters, although body 108 mayhave any one of many other geometric shapes. Body 108 may besufficiently thick to attach securely to suture 104 and to resistexcessive deformation during normal tensioning of suture 104. Body 108may be formed from a sheet of Nitinol, for example, that has a thicknessof about 0.05 to 0.2 millimeters.

Anchor 102 may include a suture 104 retained through a hole (hidden) bya knot 106. Alternately, suture 104 may be attached to anchor 102 bygluing, crimping or any one of a number of well known methods.

Self-Shielding Suture Anchor

As already described, a physician may fully penetrate the needle of asuture anchor applicator through tissue layers of an organ in order todeploy the suture anchor on the distal side of the tissue layers. Thephysician normally cannot see anatomical structures on the distal sideof the tissue layers through the endoscope and therefore mayaccidentally injure nearby organs with the penetrating needle. A fifthaspect of a suture anchor 110, a “self-shielding” suture anchor, isprovided to help prevent such accidental injury.

FIG. 16 is a perspective view and FIG. 17 is a longitudinal sectionalview of anchor 110, which includes a body 112 having a penetrating tip114, a shielding element 116 and a spring element 118. Shielding element116 may be retained in body 112 and may have a blunt end 120 that ismovable between a shielding position that is distal to penetrating tip114 and a retracted position that is proximal to penetrating tip 114.FIGS. 16 and 17 show shielding element 116 in the shielding position.Spring element 118 (FIG. 17) may be operatively associated withpenetrating element 114 and shielding element 116, such that springelement 118 may apply a predetermined spring force to bias shieldingelement 116 to the shielding position. Shielding element 116 can move tothe retracted position when blunt end 120 is pushed against tissue witha force greater than the spring force, such that penetrating tip 114 canpenetrate tissue. Once penetrating tip 114 has penetrated through thetissue, blunt end 120 can immediately extend to the shielding positionto help prevent accidental injury to nearby anatomical structures.

Still referring to FIGS. 16 and 17, body 112 may be formed into atubular shape from a stainless steel, titanium alloy, or otherbiocompatible metal. The outside diameter of body 112 may beapproximately in the range of 0.5 to 0.85 millimeters and the length maybe approximately in the range of 10 to 15 millimeters. Spring element118 may be a metallic coil compression spring that inserts easily intobody 112 or spring element 118 may be formed from any one of numerousother biocompatible materials that can provide a spring force to biasshielding element 116 to be in the shielding position. Shielding element116 may have a cylindrical, bullet shape that slides easily in body 112and may be formed from a biocompatible metal or polymer. Body 112 ofanchor 110 may include a slot 122 extending longitudinally frompenetrating tip 114 to approximately halfway between tip 114 and atrailing end 130 of body 112. A suture 128 may pass through slot 122, apassage 124 of shielding element 116 and the coils of spring element118, and may be attached to trailing end 126 by a knot 130 or by any oneof numerous other suitable methods including gluing, crimping andstaking. This attachment method of suture 128 also may function toretain shielding element 116 and spring element 118 inside of body 112.

Since anchor 110 includes a penetrating tip 114, it is not necessary forthe applicator of anchor 110 to also include a needle with a penetratingtip. For example, needle 32 of applicator 30 in FIG. 6 may be replacedwith a short tube attached to inner tube 40, or inner tube 40 may merelybe lengthened and adapted for retaining anchor 110 in a loaded position.Applicator 30 of FIG. 6 may be further modified for use with anchor 110by eliminating outer tube 42, which has a primary finction of shieldingthe penetrating tip of the needle.

Anchor 110 is an exemplary embodiment of a self-shielding anchor. Thoseskilled in the art will appreciate that numerous other embodiments arepossible, including a self-shielding anchor that is unitarily formedfrom a biocompatible material by an injection molding process.

All of the suture anchor aspects described herein and their equivalents,may be subjected to a secondary manufacturing process such as tumbling,bead blasting or electropolishing to remove sharp burrs or edges thatmay injure tissue or inhibit proper deployment into tissue. In addition,all of the suture anchor aspects may be coated with a second material inorder to provide desirable properties that may facilitate the deploymentof the anchor and/or improve the surgical outcome. For example, thesuture anchor may be coated with a lubricious coating, a polymericcoating, a drug-releasing coating, an anti-bacterial coating or acolored coating to facilitate identification.

Suture Anchor Applicator

FIG. 18A is a perspective view of a second embodiment of a suture anchorapplicator (also referred to as a medical instrument), generallydesignated 200, that is adapted to help prevent injury to nearbyanatomical structures while deploying a suture anchor. FIG. 18B is aperspective view of the distal portion of applicator 200, shown withsuture anchor 110 of FIG. 16. Applicator 200 may include an elongatedshaft 204 attached to a handle 202. Applicator 200 may be similar toapplicator 30 of FIG. 6. However, applicator 200 may also include atissue stop 206 near the distal end of shaft 204. Tissue stop 206 canfunction to control the penetration depth of the distal end of theinstrument into tissue to help prevent accidental injury totissue/organs on the distal, “blind” side of the tissue beingintentionally penetrated. Tissue stop 206 may also provide a visualindication of the needle penetration depth, as viewed through theendoscope. Applicator 200 is described next as it may be adapted for usewith suture anchor 110 of FIG. 16, although applicator 200 may also beadapted for use with many types of suture anchors, including any of thesuture anchor aspects described herein and their equivalents.

As may be seen in FIG. 18A, handle 202 may include a first actuator 208,a second actuator 210 and a third actuator 212. A physician may operatefirst actuator 208 to set the distance between the distal end ofapplicator 200 and tissue stop 206, thereby helping to control thepenetration depth of the distal end into tissue. A physician may operatesecond actuator 210 to change tissue stop 206 between a collapsed and anexpanded configuration. A physician may operate third actuator 212 todeploy suture anchor 110 into tissue, thereby attaching suture 128 tothe tissue.

FIG. 18B shows tissue stop 206 in the expanded configuration. FIGS. 19and 20 are longitudinal sectional views of the distal portion ofapplicator 200. FIG. 19 shows tissue stop 206 in the collapsedconfiguration and FIG. 20 shows tissue stop 206 in the expandedconfiguration. The distal and proximal ends of shaft 204 define alongitudinal axis 240. Axis 240 may be curvilinear if shaft 204 isadapted for use with a flexible endoscope. Shaft 204 may include aninner tube 228 having a channel 229 extending therethrough and slidablyretaining an actuating element 226. The proximal end of inner tube 228may be attached to handle 202. The proximal end of actuating element 110may be operatively connected to third actuator 212 of handle 202. Thedistal end of actuating element 226 may be operatively engaged withanchor 110, which is shown positioned inside channel 229 in a loadedposition and partially extending from a tapered distal end 230 of innertube 228. Suture 128 may be draped alongside shaft 204 for insertioninto the working channel of a flexible endoscope. When a physicianoperates third actuator 212, actuating element 226 may forcibly ejectsuture anchor 110 from inner tube 226.

An intermediate tube 222 may be movably and coaxially retained overinner tube 228. The distal end of intermediate tube 222 may include aradial flange 224. The proximal end of intermediate tube 222 may beoperatively engaged to first actuator 208. The physician may operatefirst actuator 208 to move intermediate tube 222 between an extendedposition, in which flange 224 is distal to penetrating tip 114 of anchor110, and a retracted position, in which flange 224 is proximal totapered end 230 of inner tube 228. First actuator 208 may be providedwith calibrations or a visual indicator such that the physician mayposition and hold intermediate tube 222 in any longitudinal positionbetween the extended and retracted positions and know the maximumpenetration depth of inner tube 228.

Still referring to FIGS. 19 and 20, an outer tube 214 (also referred toas a force element) may be movably and coaxially retained overintermediate tube 222. The proximal end of outer tube 214 may beoperatively connected to second actuator 210. The distal end of outertube 214 may be attached or unitarily formed with a proximal stop ring220 of tissue stop 206, which may also be coaxially retained onintermediate tube 222.

Tissue stop 206 may be formed such as by injection molding from abiocompatible polymer or metal. Tissue stop 206 may include at least onearm 216 that is approximately parallel to the longitudinal axis 240 whentissue stop 206 is in the collapsed configuration for easy passagethrough the working channel of an endoscope. Arm 216 may extendoutwardly from longitudinal axis 240 when tissue stop 206 is in theexpanded configuration, such that only the portion of applicator 200distal to tissue stop 206 may penetrate tissue. As shown in FIG. 18B,tissue stop 206 may have four arms 216 positioned around axis 240. Thedistal end of each arm may be attached to a distal stop ring 218 and theproximal end of each arm may be attached to the proximal stop ring 220.Distal stop ring 218 may be fixed to intermediate tube 222 and proximalstop ring 220 may be slidably retained on intermediate tube 222 betweenflange 224 and outer tube 214. When the physician moves second actuator210 in the distal direction, outer tube 214 can force tissue stop 206against flange 224 and cause arms 216 to buckle as shown in FIG. 24 intothe expanded configuration. The physician may move second actuator 210proximally to change tissue stop 206 back to the collapsed configurationin order to remove applicator 200 from the endoscope.

It would also be possible for proximal stop ring 220 to be fixed tointermediate tube 222 and distal stop ring 218 to be slidably retainedon intermediate tube 222. Instead of outer tube 214, another type offorce element, such as a wire (not shown) may be connected to distalring 218 and extended through channel 229 to handle 200. The proximalend of the wire force element could be connected to second actuator 210.The physician could then move second actuator 210 in the proximaldirection to change tissue stop 206 from the collapsed to the expandedconfiguration.

The longitudinal position of flange 224 may set a distance “D2” (FIG.24) between tissue stop 206 and tapered distal end 230. Penetrating tip114 of anchor 110 may extend a distance “D1” distal to tapered distaltip 230. A maximum penetration depth of tip 114, therefore, isapproximately equal to D1+D2, which may be visually indicated bycalibrations (not shown) on first actuator 208.

An alternate embodiment of applicator 200 may include a tissue stop thatis formed from a spring material such that the tissue stop is in theexpanded configuration when unconstrained. In such an alternateembodiment, the tissue stop may be attached to the distal end of anintermediate tube that the physician may move to any longitudinalposition between an extended and a retracted position. An outer sheathmay be provided on the shaft of the applicator such that the physicianmay move the sheath distally to slide over and collapse the tissue stopand may move the sheath proximally to uncover the tissue stop and allowit to expand. Calibrations may be provided on the actuator such that thephysician can know the maximal penetration depth of the tip.

FIG. 21 is a perspective view of the distal portion of a thirdembodiment of a suture anchor applicator, generally designated 300, andshowing anchor 110 (FIG. 16) having suture 128 in a loaded position inthe distal end of an inner tube 322 of a shaft 304. Applicator 300 mayinclude a tissue stop 306 that is shown in a collapsed configuration inFIG. 21 and in an expanded configuration in FIG. 22. Tissue stop 306 mayhave a pair of arms 316 that may be unitarily formed with a polymericsheath 314 covering inner tube 322. Arms 316 may be formed to be in theexpanded configuration when unconstrained, such that it is necessary forthe user to collapse arms 316 as the distal end of applicator 300 isinserted into the proximal opening of the working channel or auxiliarypassageway of the endoscope. When tissue stop 306 emerges from thedistal opening of the working channel of the endoscope, arms 316automatically spring outwardly, at least partially. When the physicianadvances applicator 300 in the distal direction such that tissue stop306 bears against the tissue being penetrated by anchor 110 and innertube 322, arms 316 further expand (if not already fully expanded) to theexpanded configuration, thereby setting a maximum penetration depth ofanchor 110 and inner tube 322 into the tissue. Withdrawal of applicator300 through the working channel of the endoscope forces tissue stop 306back into the collapsed configuration. Therefore, an outer sheath, suchas sheath 214 of applicator 200 shown in FIG. 18B, is not required forapplicator 300 in FIG. 21 to change tissue stop 306 between thecollapsed and expanded configurations.

FIGS. 23-28 illustrate applicator 300 of FIG. 21 being used to attachanchor 110 to the tissue of a patient. For clarity, the endoscope usedto provide access and visualization to the tissue is not shown, but itshould be understood that the distal end of the endoscope may also benear and directed towards the tissue to be penetrated by anchor 110.

In FIG. 23, the distal end of applicator 300 containing anchor 110 ispositioned near the tissue layers (e.g., stomach wall). Tissue stop 306is shown in the collapsed configuration, as it would be when positionedinside of the working channel of the endoscope. FIG. 24 shows shieldingelement 116 partially retracted and penetrating tip 114 of anchor 110beginning to pierce into the tissue as the user slowly pushes on theproximal end of applicator 300. FIG. 25 shows shielding element 116fully retracted into anchor 110 as penetrating tip 114 penetrates thetissue layers. FIG. 26 shows anchor 110 and the distal end of inner tube322 penetrated through the tissue layers and entering the body cavitydistal to the penetrated tissue layers. Tissue stop 306 is shown as itis pushed against the tissue layers and in the fully expandedconfiguration, thereby limiting the maximal penetration depth of anchor110 and inner tube 322. Suture 128 is shown trailing proximally throughthe tissue opening created by penetrating tip 114. FIG. 27 shows anchor110 deployed into the body cavity distal to the penetrated tissue layersand reorienting to resist pull-out from the tissue layers when a tensileforce is applied to suture 128. FIG. 28 shows anchor 110 being drawnagainst the distal side of the penetrated tissue layers as a tensileforce is lightly applied to suture 128. FIG. 28 also shows applicator300 withdrawn from the tissue and into the working channel, therebyforcing tissue stop 306 to change to the collapsed configuration forremoval from the endoscope.

A method of endoscopically attaching a suture anchor to the tissue of apatient may include the following: A suture anchor applicator whereinthe applicator includes a tissue stop movable between a collapsed and anexpanded configuration and the applicator contains a suture anchor in aloaded position. The endoscopic portion of an endoscope is positioned inthe patient to provide access and visualization of a wound in thetissue. While the tissue stop is in the collapsed configuration, theshaft of the applicator is introduced into the working channel of theendoscope. The distal end of the applicator is positioned near thetissue and the tissue stop is changed to the expanded configuration. Theapplicator is advanced distally such that the anchor and the distal endof the applicator penetrates into the tissue to approximately a maximalpenetration depth as determined by the location of the tissue stop onthe shaft of the applicator. The applicator is remotely actuated todeploy the suture anchor into the tissue, thereby attaching the sutureanchor to the tissue with the suture attached thereto and extendingthrough the penetrated tissue and the work channel. The applicator iswithdrawn proximally through the working channel and removed from theendoscope.

FIG. 29 is a perspective view of the distal portion of a fourthembodiment of a suture anchor applicator, generally designated 400, andalso referred to as a medical instrument. Applicator 400 may include atissue stop 406 (shown in an expanded configuration) having a pair ofarms 408 that may be unitarily formed with a polymeric sheath 402covering an inner tube 410. A sharp, penetrating tip 412 may be groundonto the distal end of inner tube 410 such that applicator 400 may beused with any of the suture anchors described herein. Arms 408 may beformed to be in the expanded configuration when unconstrained such thatit is necessary for the user to collapse arms 408 as the distal end ofapplicator 400 is inserted into the proximal opening of the workingchannel of the endoscope. When tissue stop 406 emerges from the distalopening of the working channel of the endoscope, arms 408 automaticallyspring outwardly, at least partially. When the physician advancesapplicator 400 in the distal direction such that a distal end 414 oftissue stop 406 bears against the tissue being penetrated by inner tube410, arms 408 may further expand (if not already fully expanded) to theexpanded configuration, thereby setting a maximum penetration depth ofinner tube 410 into the tissue. Withdrawal of applicator 400 through theworking channel of the endoscope forces tissue stop 406 back into thecollapsed configuration.

The proximal end of sheath 402 may be operatively connected to a controlon a handle (not shown) such that the longitudinal position of sheath402 relative to inner tube 410 may be adjustable by the user. Using thiscontrol, distal end 414 may be extended to a position distal topenetrating tip 412 while the distal end of applicator 400 is advancedto the wound site and retracted to a position proximal to tip 412 whenit is desired to penetrate tissue. Calibrations and/or a visualindicator may be provided on the handle to indicate the position ofdistal end 414 such that the user may know the approximate penetrationdepth of inner tube 410 into the tissue.

Although various aspects of expandable suture anchors, self-shieldingsuture anchors, suture anchor applicators and methods have been shownand described, it should be understood that modifications may occur tothose skilled in the art.

1. An expandable suture anchor for use with an applicator, the sutureanchor comprising a body formed from a biocompatible spring materialsuch that the suture anchor has a first configuration when positionedwithin the applicator and a second configuration when deployed from theapplicator, wherein the second configuration has a geometric shape thatis broader in at least one plane than the first configuration.
 2. Theexpandable suture anchor of claim 1, wherein the body has anapproximately cylindrical shape defining a longitudinal axis when in thefirst configuration.
 3. The expandable suture anchor of claim 2, whereinthe body includes at least one leg that is springably deformable suchthat a portion of the leg extends further in an outwardly direction fromthe axis in the second configuration than in the first configuration. 4.The expandable suture anchor of claim 3, wherein the body is formed froma tubular material.
 5. The expandable suture anchor of claim 2, whereinthe body has a planar shape in the second configuration.
 6. Theexpandable suture anchor of claim 5, wherein the body comprises a sheetthat is configurable into a roll.
 7. The expandable suture anchor ofclaim 5, wherein the planar shape is approximately a square shape. 8.The expandable suture anchor of claim 1, wherein the spring materialincludes at least one of a stainless steel, a titanium-nickel memorymetal, a titanium alloy, a polymer, a cellulose material, a fabric andan absorbable polymer.
 9. The expandable suture anchor of claim 1,further comprising a surgical suture connected to the body, wherein thesuture extends from approximately the middle of the body when in thesecond configuration.
 10. The expandable suture anchor of claim 9,wherein the suture is threaded through an aperture of the body and isretainably attached to the body by a knot in the suture or a ferrulecrimped onto the suture.
 11. The expandable suture anchor of claim 9,wherein the suture is fixedly attached to the body by gluing, welding,insert molding, deforming the body tightly onto the suture or amechanical attachment.
 12. The expandable suture anchor of claim 9,wherein the suture is formed from a conventional surgical suture. 13.The expandable suture anchor of claim 9, wherein the suture isapproximately 20-200 centimeters long.
 14. The expandable suture anchorof claim 1, wherein at least a portion of the suture anchor is coatedwith at least one of a lubricating coating, a polymeric coating, ananti-bacterial coating, a drug-releasing coating and a colored coating.15. The expandable suture anchor of claim 1, wherein the body is formedto be normally in the expanded configuration such that the body isconstrained in the first configuration when loaded within theapplicator.
 16. An expandable suture anchor for use with an applicator,the suture anchor comprising: a body formed from a nickel-titaniummemory material such that the suture anchor has a first configurationwhen positioned within the applicator and a second configuration afterdeployment from the applicator, wherein the second configuration has ageometric shape that is broader in at least one plane than the firstconfiguration, and wherein the body has an approximately cylindricalshape defining a longitudinal axis when in the first configuration, andwherein the body includes at least one leg that is springably deformablesuch that a portion of the leg extends further in an outwardly directionfrom the axis in the second configuration than in the firstconfiguration; and a surgical suture threaded through an aperture of thebody and retainably attached to the body by a knot in the suture or aferrule crimped onto the suture to the body, wherein the suture extendsfrom approximately the middle of the body when in the secondconfiguration.
 17. The expandable suture anchor of claim 16, wherein thesuture is formed from a conventional surgical suture.
 18. The expandablesuture anchor of claim 17, wherein the suture is approximately 20-200centimeters long.
 19. The expandable suture anchor of claim 16, whereinat least a portion of the suture anchor is coated with at least one of alubricating coating, a polymeric coating, an anti-bacterial coating, adrug-releasing coating and a colored coating.
 20. The expandable sutureanchor of claim 16, wherein the body is formed to be normally in theexpanded configuration such that the body is constrained in the firstconfiguration when loaded within the applicator.